Chaindoc Webhooks

当您的Chaindoc账户发生事件时,实时接收通知。Webhooks将事件数据即时推送至您的服务器,无需轮询。

概述

Chaindoc Webhooks 允许您的应用在账户发生事件时接收实时通知。无需轮询 API,一旦操作发生,Webhooks 便会立即将事件数据推送至您的服务器。

主要功能

  • 实时通知 - 即时将事件推送至您的服务器
  • 自动重试 - 支持最多3次重试,采用指数级后退机制
  • 签名验证 - 采用HMAC SHA256确保有效负载真实性
  • 事件过滤 - 仅接收您关注的事件
  • 错误追踪 - 监控Webhook发送状态及失败情况

使用场景

  • 当文件签署时发送邮件通知
  • 当文件在区块链上完成验证时触发工作流
  • 当签名请求创建时更新您的数据库
  • 与外部系统同步文档状态
  • 审计追踪与合规日志记录

设置

步骤1:创建API密钥

在 Chaindoc 仪表盘中导航至“设置 → API 访问”,创建一个启用 webhook 配置的 API 密钥。

步骤 2:配置 Webhook URL

使用API配置您的webhook端点:

terminal
curl -X PATCH https://api.chaindoc.io/user/api-access/1/config \
  -H "Authorization: Bearer your_auth_token" \
  -H "Content-Type: application/json" \
  -d '{
    "webhookUrl": "https://yourapp.com/webhooks/chaindoc",
    "webhookEnabled": true,
    "webhookSecret": "your_secure_random_string"
  }'

步骤3:实现Webhook端点

在服务器上创建一个端点以接收 webhook 事件。以下是不同语言的示例:

const express = require('express');
const crypto = require('crypto');

const app = express();
app.use(express.json());

app.post('/webhooks/chaindoc', (req, res) => {
  const signature = req.headers['x-webhook-signature'];
  const eventType = req.headers['x-webhook-event'];
  
  // Verify signature
  if (!verifySignature(req.body, signature, process.env.WEBHOOK_SECRET)) {
    return res.status(401).send('Invalid signature');
  }
  
  // Process event
  console.log('Received event:', eventType, req.body);
  
  // Handle different event types
  switch (eventType) {
    case 'document.created':
      handleDocumentCreated(req.body);
      break;
    case 'document.verified':
      handleDocumentVerified(req.body);
      break;
    case 'signature.request.completed':
      handleSignatureCompleted(req.body);
      break;
  }
  
  // Always respond with 200 OK
  res.status(200).send('Webhook received');
});

function verifySignature(payload, signature, secret) {
  const hmac = crypto.createHmac('sha256', secret);
  const digest = hmac.update(JSON.stringify(payload)).digest('hex');
  return crypto.timingSafeEqual(
    Buffer.from(signature),
    Buffer.from(digest)
  );
}

app.listen(3000);

活动类型

Chaindoc会在以下事件发生时发送webhook:

文档创建时间

当通过API创建新文档时触发。

terminal
{
  "event": "document.created",
  "documentId": "86840ee4-8bf2-4a91-a289-e99d8307ec25",
  "name": "Service Agreement",
  "timestamp": "2024-12-04T10:30:00.000Z"
}

document.verified

当文档在区块链上成功验证时触发。

terminal
{
  "event": "document.verified",
  "documentId": "86840ee4-8bf2-4a91-a289-e99d8307ec25",
  "versionId": "f0b7721f-0399-4035-9b69-7b95d3a367f0",
  "txHash": "0x789ghi...",
  "chainId": 137,
  "timestamp": "2024-12-04T10:35:00.000Z"
}

document.signed

当所有必需签名收集完毕时触发。

terminal
{
  "event": "document.signed",
  "documentId": "86840ee4-8bf2-4a91-a289-e99d8307ec25",
  "signatureRequestId": "req_21096b94498f4a2d9795e810edc2c9a9",
  "signers": [
    {
      "email": "signer1@example.com",
      "signedAt": "2024-12-04T10:30:00.000Z"
    },
    {
      "email": "signer2@example.com",
      "signedAt": "2024-12-04T10:32:00.000Z"
    }
  ],
  "timestamp": "2024-12-04T10:32:00.000Z"
}

signature.request.created

当创建新的签名请求时触发。

terminal
{
  "event": "signature.request.created",
  "signatureRequestId": "req_21096b94498f4a2d9795e810edc2c9a9",
  "documentId": "86840ee4-8bf2-4a91-a289-e99d8307ec25",
  "recipients": [
    {"email": "signer1@example.com"},
    {"email": "signer2@example.com"}
  ],
  "deadline": "2024-12-31T23:59:59.000Z",
  "timestamp": "2024-12-04T10:30:00.000Z"
}

signature.request.completed

当所有签署人完成签名时触发。

terminal
{
  "event": "signature.request.completed",
  "signatureRequestId": "req_21096b94498f4a2d9795e810edc2c9a9",
  "documentId": "86840ee4-8bf2-4a91-a289-e99d8307ec25",
  "completedAt": "2024-12-04T10:32:00.000Z",
  "timestamp": "2024-12-04T10:32:00.000Z"
}

签名请求被拒绝

当签名者拒绝签名请求时触发。

terminal
{
  "event": "signature.request.rejected",
  "signatureRequestId": "req_21096b94498f4a2d9795e810edc2c9a9",
  "documentId": "86840ee4-8bf2-4a91-a289-e99d8307ec25",
  "rejectedBy": "signer1@example.com",
  "reason": "Terms not acceptable",
  "timestamp": "2024-12-04T10:30:00.000Z"
}

安全

签名验证

Chaindoc使用HMAC SHA256对所有webhook有效负载进行签名。请务必验证签名以确保真实性并防止重放攻击。

签名验证机制说明

1Chaindoc 生成签名Chaindoc使用您的webhook密钥生成HMAC签名

2签名已发送至标题签名通过X-Webhook-Signature标头发送

3您的服务器验证您的服务器将重新计算签名,并使用时序安全函数进行比对

const crypto = require('crypto');

function verifyWebhookSignature(payload, signature, secret) {
  const hmac = crypto.createHmac('sha256', secret);
  const digest = hmac.update(JSON.stringify(payload)).digest('hex');
  
  // Use timing-safe comparison to prevent timing attacks
  return crypto.timingSafeEqual(
    Buffer.from(signature),
    Buffer.from(digest)
  );
}

// Usage
const isValid = verifyWebhookSignature(
  req.body,
  req.headers['x-webhook-signature'],
  process.env.WEBHOOK_SECRET
);

if (!isValid) {
  return res.status(401).send('Invalid signature');
}

重试逻辑

Chaindoc会自动对失败的webhook发送进行指数级后退重试。

  • 首次重试:1分钟后
  • 第二次重试:5分钟后(总计:6分钟)
  • 第三次重试:15分钟后(累计:21分钟)

测试 Webhooks

本地开发

使用ngrok等工具将本地服务器暴露出来进行webhook测试:

terminal
# Install ngrok
npm install -g ngrok

# Start your local server
node server.js

# Expose port 3000
ngrok http 3000

# Use the ngrok URL as your webhook endpoint
# Example: https://abc123.ngrok.io/webhooks/chaindoc

手动测试

使用示例有效负载测试您的 webhook 端点:

terminal
curl -X POST https://yourapp.com/webhooks/chaindoc \
  -H "Content-Type: application/json" \
  -H "X-Webhook-Event: document.created" \
  -H "X-Webhook-Signature: test_signature" \
  -d '{
    "event": "document.created",
    "documentId": "test-123",
    "name": "Test Document",
    "timestamp": "2024-12-04T10:30:00.000Z"
  }'

最佳实践

  • 处理前务必验证Webhook签名
  • 请快速响应(30秒内)以避免超时
  • 在队列中异步处理Webhook
  • 实现幂等性以处理重复事件
  • 记录所有Webhook事件以供调试和审计
  • 在控制台中监控 webhook 发送失败情况
  • 为保障安全,请使用HTTPS接口
  • 优雅处理所有事件类型(忽略未知事件)

完整示例

以下是一个具备数据库集成的生产就绪型Webhook处理程序:

webhooks/chaindoc.ts
import express from 'express';
import crypto from 'crypto';
import { PrismaClient } from '@prisma/client';

const app = express();
const prisma = new PrismaClient();

app.use(express.json());

app.post('/webhooks/chaindoc', async (req, res) => {
  const signature = req.headers['x-webhook-signature'] as string;
  const eventType = req.headers['x-webhook-event'] as string;
  const payload = req.body;
  
  // 1. Verify signature
  if (!verifySignature(payload, signature, process.env.WEBHOOK_SECRET!)) {
    console.error('Invalid webhook signature');
    return res.status(401).json({ error: 'Invalid signature' });
  }
  
  // 2. Check for duplicate events (idempotency)
  const eventId = `${eventType}-${payload.timestamp}`;
  const existing = await prisma.webhookEvent.findUnique({
    where: { eventId },
  });
  
  if (existing) {
    console.log('Duplicate event, skipping:', eventId);
    return res.status(200).json({ status: 'duplicate' });
  }
  
  // 3. Store event
  await prisma.webhookEvent.create({
    data: {
      eventId,
      eventType,
      payload,
      processedAt: new Date(),
    },
  });
  
  // 4. Process event asynchronously
  processWebhookAsync(eventType, payload).catch((error) => {
    console.error('Error processing webhook:', error);
  });
  
  // 5. Respond immediately
  res.status(200).json({ status: 'received' });
});

async function processWebhookAsync(eventType: string, payload: any) {
  switch (eventType) {
    case 'document.verified':
      await handleDocumentVerified(payload);
      break;
    case 'signature.request.completed':
      await handleSignatureCompleted(payload);
      await sendNotificationEmail(payload);
      break;
    case 'signature.request.rejected':
      await handleSignatureRejected(payload);
      break;
  }
}

async function handleDocumentVerified(payload: any) {
  await prisma.document.update({
    where: { id: payload.documentId },
    data: {
      status: 'verified',
      blockchainTxHash: payload.txHash,
      verifiedAt: new Date(payload.timestamp),
    },
  });
}

async function handleSignatureCompleted(payload: any) {
  await prisma.signatureRequest.update({
    where: { id: payload.signatureRequestId },
    data: {
      status: 'completed',
      completedAt: new Date(payload.completedAt),
    },
  });
}

function verifySignature(payload: any, signature: string, secret: string): boolean {
  const hmac = crypto.createHmac('sha256', secret);
  const digest = hmac.update(JSON.stringify(payload)).digest('hex');
  return crypto.timingSafeEqual(Buffer.from(signature), Buffer.from(digest));
}

app.listen(3000);